i77: capitalize time frequency in datasets database

When a query is iniated with DataQuery, the time_frequency parameter
is lowered to ensure it is compatible with the string format in the
database. When the time_frequency attribute is extracted from the
database is put into title case.
Changing the selection behavior of the Data Selection widgets.
Fixing problem with metadata ajax call.
Inserting example programs to query the datasets database.
mark - error in dataset category